A couple live in an old, isolated mansion. The husband's murderous, insane twin escapes from a lunatic asylum. The cops haul off the wrong twin and the wife is stuck with the killer.
Unfortunately the movie Mark of Cain is not yet available on HBO Max.
| Production | Anthony Kramreither | Producer |
| Writing | Peter Colley | Writer |
| Editing | Margaret Van Eerdewijk | Editor |
| Camera | John Herzog | Director of Photography |
| Directing | Bruce Pittman | Director |
| Writing | John Sheppard | Writer |
| Sound | Bruce Ley | Original Music Composer |
